The one thing I would advise against is buying a "set". You will usually wind up with a few tools you will seldom, if ever, use.
For starters, I would get a 1/2 or 3/8 spindle gouge, a half inch round nose scraper, and a half inch skew chisel. That will get you started, and before you know it, you will soon be caught in the one tool away from greatness vortex.
I have no experience with the various EZ Tools carbide tipped tools, but they have a following.
Whatever you get, get good. Buy from someone like Woodcraft, Rockler, or, my personal favorite, Packard Woodworks. Some of the tools you see on a certain well known online auction might seem like a good deal but it is pure junk. That doesn't mean you can't find good deals there, it just means you need to be careful.
When I bought my PM3520 it was around three grand. With the help of some hollowing rigs and a vacuum chuck set up, there is probably almost that much in tools to play with it. The only limitation is hard hard the bug bites you. In my case, it's everything from 16 inch diameter bowls to dollhouse scale lidded candy dishes.